1. Field of the Invention
The present invention relates to devices which are fastened to flexible packaging to assist in tearing open the packaging without the use of an additional tool.
2. Description of Related Art
A major consideration in designing packaging for various consumer products is the manner in which the packaging may be opened by the end user of the product. As an example, steel and aluminum cans have long been used to contain individual servings of carbonated and non-carbonated beverages. Initially, such cans required the use of an additional tool, the can opener, to pierce an opening or openings in the lid portion of the can in order to extract the beverage. A significant disadvantage associated with this type of packaging was that can openers were not always readily available when a person wished to open the can.
Recognizing this disadvantage, package designers developed the "flip-top" can, which now enjoys widespread use in individual serving sized cans. The flip-top employs the physical principles of leverage and isolation of stressed material to eliminate the need for an additional tool, such as the can opener, because a leveraging means and a weakened region of the lid are provided on each can. Consumer reaction to this and other improvements, however slight, in package opening convenience has been so overwhelmingly positive that it is presently difficult to find cans or boxes requiring additional tools to open them.
In the field of flexible packaging, e.g., polymeric bags, however, one often finds that opening the package requires a separate or additional tool such as a pair of scissors, a knife, or one of numerous tools sold for the express purpose of performing the package opening function. While most flexible packaging for consumer goods is ostensibly designed to be opened with normal manual effort, in reality many of these packages require near-superhuman effort to effect the opening of the package, and many consumers thus resort to the use of an opening tool.
Numerous approaches have been taken to alleviate the problem of opening bag-type flexible packaging without the need for an additional tool. Slits or v-notches have been provided on the edges of packages in order to provide a tear initiation site, which overcomes one problem associated with the opening of flexible packaging. Some packaging designs have employed a weakened line of material extending through the package which is somewhat similar in concept to scoring the lid of a flip-top can in that the weakened line provides a "path of least resistance" for tear propagation, and tends to concentrate tearing stresses in that region. It should be readily apparent that employing weakened lines in the packaging material has the disadvantage that the package might be inadvertently opened in the transportation or handling of the packages prior to reaching the end user.
Tear strips or tear strings have also been employed in flexible packaging in order to avoid the necessity of using an opening tool. The use of tear strips or tear strings often complicates the packaging operation itself, thereby driving up the product manufacturing cost, which is ultimately passed on to the consumer. Finger or hand grasping means have previously been employed in attempts to facilitate the opening of flexible packaging. The grasping means previously employed have generally been integral extensions of the packaging material itself, or exposed extensions of tear strips or tear strings. Such grasping means, while improving the ability to apply tearing forces to the package, have not provided any substantial force magnification or stress concentration which would ease the opening of the package.
It is therefore an important object of the present invention to provide an opening device which is fixedly attached to a flexible packaging container, and which provides multiplication of tearing forces and concentration of tearing stress in an isolated region of the packaging to facilitate the opening of the packaging by exertion of manual force.
It is a further important object of the present invention to provide an opening device which is to be fixedly attached to a flexible packaging container and which comprises a pair of closely spaced wing-like members or levers, the distal ends of which extend from a peripheral edge of the packaging, the wing-like members having a common fulcrum at their proximal ends wherein a proximal end portion of each wing is secured to the packaging.
It is another important object of the present invention to provide a flexible package opening device made of a relatively inexpensive material and which is further easily secured to the flexible package as the package is formed and sealed, the opening device providing means for concentrating and isolating tearing stresses at a predetermined narrow region of the package and a means for increasing a tearing force exerted by a person opening the package.
It is an additional object of the present invention to provide a device to be secured to a flexible packaging material which provides magnified application of tearing forces through leverage and concentration of the tearing forces at a predetermined area, which device takes advantage of the ability of the contents of the package to provide a bearing surface against which a proximal end of the device secured to the packaging material will pivot as a fulcrum.